There’s recent research by Beakcheol Jang, Hyunjung Kim and Jong Wook Ki of Sangmyung University, S Korea on An Accurate Indoor Positioning Algorithm Using Sensors and Crowdsourced Landmarks.
![](https://www.beaconzone.co.uk/blog/wp-content/uploads/2019/10/indoorpositioningsystem.png)
The paper describes how to obtain more accurate heading direction and user coordinates by combining smartphone sensors and iBeacons as landmarks.